(1) Field of the Invention
The present invention relates to a paper sheet folding apparatus and, more particularly, to a paper sheet folding apparatus for folding a continuous paper sheet having folding lines at predetermined intervals in such a manner that one side and the other side of the paper sheet alternately face up.
(2) Description of the Prior Art
In an image forming apparatus such as a printer or copying machine, after images have been formed on a continuous paper sheet in an image forming station, the continuous paper sheet is sequentially folded on folding lines by means of a paper sheet folding apparatus that is provided in the end of the paper delivery path, in such a manner that one side and the other side of the paper sheet alternately face up.
A prior art paper sheet folding apparatus comprises, as shown in FIG. 7, (i) a paper guide 51 disposed in a fixed condition, (ii) a feed roller 53 for letting out a continuous paper sheet 52 along the paper guide 51 and (iii) a swing guide 54 that is disposed under the paper guide 51 and swings through a specified angle. The continuous paper sheet 52, which has been let out downwards along the paper guide 51, is swayed back and forth (from side to side in FIG. 7) by the swing guide 54 at folding line intervals so that the sheet 52 is folded on a paper receiving table 55 such that one side and the other side alternately face up in a regular manner.